Studies on Hemolysis due to the Administration of High Dose Fentanyl : Experimental Studies on Hemolysis due to the Administration of Fentanyl Solution

High dose fentanyl has been known to produce adequate anesthesia with minimal change in cardiovascular hemodynamics in cardiac patients undergoing surgery. However hemolysis has been recognized after the administration of high dose fentanyl, which has never been reported in detail. The etiologic factors might be due to the effect of the large dose of fentanyl itself or preservatives contained in the ampule. Changes of osmotic pressure caused by a large volume of hypo-osmotic solution also may be a factor of hemolysis. The author intended to clarify the mechanisms of the hemolysis after the administration of high dose fentanyl. The results were as follows: 1. Five solutions per 1.1ml were added to 2.0ml of the red blood cell in saline. A significant increase in hemoglobin and potassium concentration and a significant decrease in osmotic pressure and sodium concentration in the supernatant of the mixture with fentanyl+saline and hypo-osmotic solution+saline were observed as compared to saline alone, preservatives+saline, and isotonic fentanyl+10%NaCl. 2. Five solutions per 0.55, 0.11 and 0.055ml were added to the red blood cell in saline. There was a significant increase in hemoglobin and potassium concentration of the supernatant of the mixture with the groups larger than fentanyl solution 0.5ml in a total volume of 3.1ml compared to saline alone. In conclusion: The mechanism of hemolysis was found to be a hypotonic local hemolysis. Therefore, large volumes of fentanyl should be administered in isotonic fluid by the addition of an adequate amount of 10%NaCl solution and the speed of injection should be slowed via the peripheral vein or preferably via the central vein.departmental bulletin pape